A conventional car lighter plug has an insertion portion, which has an elastic conducting post disposed at the front end thereof. Projective elastic conducting sheets are disposed at the side face of the insertion portion. The insertion portion can be inserted into a car lighter insertion hole to let the elastic conducting post and the elastic conducting sheets of the insertion portion achieve electric connection with corresponding conducting terminals in the car lighter insertion hole so that electricity can be transferred to the car lighter plug. The car lighter plug can also be connected to a lighter, a charger, or an electronic device so that electricity can be transferred to the lighter, the charger, or the electronic device.
Besides, there is also a kind of car lighter plug with an angle-adjustable joint structure thereon. A user can adjust various kinds of a car lighter, a charger, or an electronic device according to practical necessity to facilitate use.
However, the joint structure of the conventional car lighter plug utilizes a ratchet wheel or a friction face to fix the already adjusted angle. After a period time of use, the situation of slide may arise due to factors like abrasion so that the already adjusted angle cannot be firmly fixed.
Accordingly, the above conventional car lighter plug has inconvenience and drawbacks in practical use. The present invention aims to resolve the problems in the prior art.